EDAC/igen6: Add EDAC driver for Intel client SoCs using IBECC

This driver supports Intel client SoC with integrated memory controller
using In-Band ECC(IBECC). The memory correctable and uncorrectable errors
are reported via NMIs. The driver handles the NMIs and decodes the memory
error address to platform specific address. The first IBECC-supported SoC
is Elkhart Lake.

[Tony: s/#include <linux/nmi.h>/#include <asm/nmi.h>/ to fix randconfig build]
Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

drivers/edac/Kconfig

@@ -269,6 +269,15 @@ config EDAC_PND2
 	  first used on the Apollo Lake platform and Denverton
 	  micro-server but may appear on others in the future.
 
+config EDAC_IGEN6
+	tristate "Intel client SoC Integrated MC"
+	depends on PCI && X86_64 && PCI_MMCONFIG && ARCH_HAVE_NMI_SAFE_CMPXCHG
+	help
+	  Support for error detection and correction on the Intel
+	  client SoC Integrated Memory Controller using In-Band ECC IP.
+	  This In-Band ECC is first used on the Elkhart Lake SoC but
+	  may appear on others in the future.
+
 config EDAC_MPC85XX
 	bool "Freescale MPC83xx / MPC85xx"
 	depends on FSL_SOC && EDAC=y

drivers/edac/Makefile

@@ -32,6 +32,7 @@ obj-$(CONFIG_EDAC_I7300)		+= i7300_edac.o
 obj-$(CONFIG_EDAC_I7CORE)		+= i7core_edac.o
 obj-$(CONFIG_EDAC_SBRIDGE)		+= sb_edac.o
 obj-$(CONFIG_EDAC_PND2)			+= pnd2_edac.o
+obj-$(CONFIG_EDAC_IGEN6)			+= igen6_edac.o
 obj-$(CONFIG_EDAC_E7XXX)		+= e7xxx_edac.o
 obj-$(CONFIG_EDAC_E752X)		+= e752x_edac.o
 obj-$(CONFIG_EDAC_I82443BXGX)		+= i82443bxgx_edac.o

drivers/edac/igen6_edac.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for Intel client SoC with integrated memory controller using IBECC
+ *
+ * Copyright (C) 2020 Intel Corporation
+ *
+ * The In-Band ECC (IBECC) IP provides ECC protection to all or specific
+ * regions of the physical memory space. It's used for memory controllers
+ * that don't support the out-of-band ECC which often needs an additional
+ * storage device to each channel for storing ECC data.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+#include <linux/slab.h>
+#include <linux/irq_work.h>
+#include <linux/llist.h>
+#include <linux/genalloc.h>
+#include <linux/edac.h>
+#include <linux/bits.h>
+#include <linux/io.h>
+#include <asm/mach_traps.h>
+#include <asm/nmi.h>
+
+#include "edac_mc.h"
+#include "edac_module.h"
+
+#define IGEN6_REVISION	"v2.4"
+
+#define EDAC_MOD_STR	"igen6_edac"
+#define IGEN6_NMI_NAME	"igen6_ibecc"
+
+/* Debug macros */
+#define igen6_printk(level, fmt, arg...)		\
+	edac_printk(level, "igen6", fmt, ##arg)
+
+#define igen6_mc_printk(mci, level, fmt, arg...)	\
+	edac_mc_chipset_printk(mci, level, "igen6", fmt, ##arg)
+
+#define GET_BITFIELD(v, lo, hi) (((v) & GENMASK_ULL(hi, lo)) >> (lo))
+
+#define NUM_IMC				1 /* Max memory controllers */
+#define NUM_CHANNELS			2 /* Max channels */
+#define NUM_DIMMS			2 /* Max DIMMs per channel */
+
+#define _4GB				BIT_ULL(32)
+
+/* Size of physical memory */
+#define TOM_OFFSET			0xa0
+/* Top of low usable DRAM */
+#define TOLUD_OFFSET			0xbc
+/* Capability register C */
+#define CAPID_C_OFFSET			0xec
+#define CAPID_C_IBECC			BIT(15)
+
+/* Error Status */
+#define ERRSTS_OFFSET			0xc8
+#define ERRSTS_CE			BIT_ULL(6)
+#define ERRSTS_UE			BIT_ULL(7)
+
+/* Error Command */
+#define ERRCMD_OFFSET			0xca
+#define ERRCMD_CE			BIT_ULL(6)
+#define ERRCMD_UE			BIT_ULL(7)
+
+/* IBECC MMIO base address */
+#define IBECC_BASE			(res_cfg->ibecc_base)
+#define IBECC_ACTIVATE_OFFSET		IBECC_BASE
+#define IBECC_ACTIVATE_EN		BIT(0)
+
+/* IBECC error log */
+#define ECC_ERROR_LOG_OFFSET		(IBECC_BASE + 0x170)
+#define ECC_ERROR_LOG_CE		BIT_ULL(62)
+#define ECC_ERROR_LOG_UE		BIT_ULL(63)
+#define ECC_ERROR_LOG_ADDR_SHIFT	5
+#define ECC_ERROR_LOG_ADDR(v)		GET_BITFIELD(v, 5, 38)
+#define ECC_ERROR_LOG_SYND(v)		GET_BITFIELD(v, 46, 61)
+
+/* Host MMIO base address */
+#define MCHBAR_OFFSET			0x48
+#define MCHBAR_EN			BIT_ULL(0)
+#define MCHBAR_BASE(v)			(GET_BITFIELD(v, 16, 38) << 16)
+#define MCHBAR_SIZE			0x10000
+
+/* Parameters for the channel decode stage */
+#define MAD_INTER_CHANNEL_OFFSET	0x5000
+#define MAD_INTER_CHANNEL_DDR_TYPE(v)	GET_BITFIELD(v, 0, 2)
+#define MAD_INTER_CHANNEL_ECHM(v)	GET_BITFIELD(v, 3, 3)
+#define MAD_INTER_CHANNEL_CH_L_MAP(v)	GET_BITFIELD(v, 4, 4)
+#define MAD_INTER_CHANNEL_CH_S_SIZE(v)	((u64)GET_BITFIELD(v, 12, 19) << 29)
+
+/* Parameters for DRAM decode stage */
+#define MAD_INTRA_CH0_OFFSET		0x5004
+#define MAD_INTRA_CH_DIMM_L_MAP(v)	GET_BITFIELD(v, 0, 0)
+
+/* DIMM characteristics */
+#define MAD_DIMM_CH0_OFFSET		0x500c
+#define MAD_DIMM_CH_DIMM_L_SIZE(v)	((u64)GET_BITFIELD(v, 0, 6) << 29)
+#define MAD_DIMM_CH_DLW(v)		GET_BITFIELD(v, 7, 8)
+#define MAD_DIMM_CH_DIMM_S_SIZE(v)	((u64)GET_BITFIELD(v, 16, 22) << 29)
+#define MAD_DIMM_CH_DSW(v)		GET_BITFIELD(v, 24, 25)
+
+/* Hash for channel selection */
+#define CHANNEL_HASH_OFFSET		0X5024
+/* Hash for enhanced channel selection */
+#define CHANNEL_EHASH_OFFSET		0X5028
+#define CHANNEL_HASH_MASK(v)		(GET_BITFIELD(v, 6, 19) << 6)
+#define CHANNEL_HASH_LSB_MASK_BIT(v)	GET_BITFIELD(v, 24, 26)
+#define CHANNEL_HASH_MODE(v)		GET_BITFIELD(v, 28, 28)
+
+static struct res_config {
+	int num_imc;
+	u32 ibecc_base;
+	bool (*ibecc_available)(struct pci_dev *pdev);
+	/* Convert error address logged in IBECC to system physical address */
+	u64 (*err_addr_to_sys_addr)(u64 eaddr);
+	/* Convert error address logged in IBECC to integrated memory controller address */
+	u64 (*err_addr_to_imc_addr)(u64 eaddr);
+} *res_cfg;
+
+struct igen6_imc {
+	int mc;
+	struct mem_ctl_info *mci;
+	struct pci_dev *pdev;
+	struct device dev;
+	void __iomem *window;
+	u64 ch_s_size;
+	int ch_l_map;
+	u64 dimm_s_size[NUM_CHANNELS];
+	u64 dimm_l_size[NUM_CHANNELS];
+	int dimm_l_map[NUM_CHANNELS];
+};
+
+static struct igen6_pvt {
+	struct igen6_imc imc[NUM_IMC];
+} *igen6_pvt;
+
+/* The top of low usable DRAM */
+static u32 igen6_tolud;
+/* The size of physical memory */
+static u64 igen6_tom;
+
+struct decoded_addr {
+	int mc;
+	u64 imc_addr;
+	u64 sys_addr;
+	int channel_idx;
+	u64 channel_addr;
+	int sub_channel_idx;
+	u64 sub_channel_addr;
+};
+
+struct ecclog_node {
+	struct llist_node llnode;
+	int mc;
+	u64 ecclog;
+};
+
+/*
+ * In the NMI handler, the driver uses the lock-less memory allocator
+ * to allocate memory to store the IBECC error logs and links the logs
+ * to the lock-less list. Delay printk() and the work of error reporting
+ * to EDAC core in a worker.
+ */
+#define ECCLOG_POOL_SIZE	PAGE_SIZE
+LLIST_HEAD(ecclog_llist);
+static struct gen_pool *ecclog_pool;
+static char ecclog_buf[ECCLOG_POOL_SIZE];
+static struct irq_work ecclog_irq_work;
+static struct work_struct ecclog_work;
+
+/* Compute die IDs for Elkhart Lake with IBECC */
+#define DID_EHL_SKU5	0x4514
+#define DID_EHL_SKU6	0x4528
+#define DID_EHL_SKU7	0x452a
+#define DID_EHL_SKU8	0x4516
+#define DID_EHL_SKU9	0x452c
+#define DID_EHL_SKU10	0x452e
+#define DID_EHL_SKU11	0x4532
+#define DID_EHL_SKU12	0x4518
+#define DID_EHL_SKU13	0x451a
+#define DID_EHL_SKU14	0x4534
+#define DID_EHL_SKU15	0x4536
+
+static bool ehl_ibecc_available(struct pci_dev *pdev)
+{
+	u32 v;
+
+	if (pci_read_config_dword(pdev, CAPID_C_OFFSET, &v))
+		return false;
+
+	return !!(CAPID_C_IBECC & v);
+}
+
+static u64 ehl_err_addr_to_sys_addr(u64 eaddr)
+{
+	return eaddr;
+}
+
+static u64 ehl_err_addr_to_imc_addr(u64 eaddr)
+{
+	if (eaddr < igen6_tolud)
+		return eaddr;
+
+	if (igen6_tom <= _4GB)
+		return eaddr + igen6_tolud - _4GB;
+
+	if (eaddr < _4GB)
+		return eaddr + igen6_tolud - igen6_tom;
+
+	return eaddr;
+}
+
+static struct res_config ehl_cfg = {
+	.num_imc	 = 1,
+	.ibecc_base	 = 0xdc00,
+	.ibecc_available = ehl_ibecc_available,
+	.err_addr_to_sys_addr  = ehl_err_addr_to_sys_addr,
+	.err_addr_to_imc_addr  = ehl_err_addr_to_imc_addr,
+};
+
+static const struct pci_device_id igen6_pci_tbl[] = {
+	{ PCI_VDEVICE(INTEL, DID_EHL_SKU5), (kernel_ulong_t)&ehl_cfg },
+	{ PCI_VDEVICE(INTEL, DID_EHL_SKU6), (kernel_ulong_t)&ehl_cfg },
+	{ PCI_VDEVICE(INTEL, DID_EHL_SKU7), (kernel_ulong_t)&ehl_cfg },
+	{ PCI_VDEVICE(INTEL, DID_EHL_SKU8), (kernel_ulong_t)&ehl_cfg },
+	{ PCI_VDEVICE(INTEL, DID_EHL_SKU9), (kernel_ulong_t)&ehl_cfg },
+	{ PCI_VDEVICE(INTEL, DID_EHL_SKU10), (kernel_ulong_t)&ehl_cfg },
+	{ PCI_VDEVICE(INTEL, DID_EHL_SKU11), (kernel_ulong_t)&ehl_cfg },
+	{ PCI_VDEVICE(INTEL, DID_EHL_SKU12), (kernel_ulong_t)&ehl_cfg },
+	{ PCI_VDEVICE(INTEL, DID_EHL_SKU13), (kernel_ulong_t)&ehl_cfg },
+	{ PCI_VDEVICE(INTEL, DID_EHL_SKU14), (kernel_ulong_t)&ehl_cfg },
+	{ PCI_VDEVICE(INTEL, DID_EHL_SKU15), (kernel_ulong_t)&ehl_cfg },
+	{ },
+};
+MODULE_DEVICE_TABLE(pci, igen6_pci_tbl);
+
+static enum dev_type get_width(int dimm_l, u32 mad_dimm)
+{
+	u32 w = dimm_l ? MAD_DIMM_CH_DLW(mad_dimm) :
+			 MAD_DIMM_CH_DSW(mad_dimm);
+
+	switch (w) {
+	case 0:
+		return DEV_X8;
+	case 1:
+		return DEV_X16;
+	case 2:
+		return DEV_X32;
+	default:
+		return DEV_UNKNOWN;
+	}
+}
+
+static enum mem_type get_memory_type(u32 mad_inter)
+{
+	u32 t = MAD_INTER_CHANNEL_DDR_TYPE(mad_inter);
+
+	switch (t) {
+	case 0:
+		return MEM_DDR4;
+	case 1:
+		return MEM_DDR3;
+	case 2:
+		return MEM_LPDDR3;
+	case 3:
+		return MEM_LPDDR4;
+	case 4:
+		return MEM_WIO2;
+	default:
+		return MEM_UNKNOWN;
+	}
+}
+
+static int decode_chan_idx(u64 addr, u64 mask, int intlv_bit)
+{
+	u64 hash_addr = addr & mask, hash = 0;
+	u64 intlv = (addr >> intlv_bit) & 1;
+	int i;
+
+	for (i = 6; i < 20; i++)
+		hash ^= (hash_addr >> i) & 1;
+
+	return (int)hash ^ intlv;
+}
+
+static u64 decode_channel_addr(u64 addr, int intlv_bit)
+{
+	u64 channel_addr;
+
+	/* Remove the interleave bit and shift upper part down to fill gap */
+	channel_addr  = GET_BITFIELD(addr, intlv_bit + 1, 63) << intlv_bit;
+	channel_addr |= GET_BITFIELD(addr, 0, intlv_bit - 1);
+
+	return channel_addr;
+}
+
+static void decode_addr(u64 addr, u32 hash, u64 s_size, int l_map,
+			int *idx, u64 *sub_addr)
+{
+	int intlv_bit = CHANNEL_HASH_LSB_MASK_BIT(hash) + 6;
+
+	if (addr > 2 * s_size) {
+		*sub_addr = addr - s_size;
+		*idx = l_map;
+		return;
+	}
+
+	if (CHANNEL_HASH_MODE(hash)) {
+		*sub_addr = decode_channel_addr(addr, intlv_bit);
+		*idx = decode_chan_idx(addr, CHANNEL_HASH_MASK(hash), intlv_bit);
+	} else {
+		*sub_addr = decode_channel_addr(addr, 6);
+		*idx = GET_BITFIELD(addr, 6, 6);
+	}
+}
+
+static int igen6_decode(struct decoded_addr *res)
+{
+	struct igen6_imc *imc = &igen6_pvt->imc[res->mc];
+	u64 addr = res->imc_addr, sub_addr, s_size;
+	int idx, l_map;
+	u32 hash;
+
+	if (addr >= igen6_tom) {
+		edac_dbg(0, "Address 0x%llx out of range\n", addr);
+		return -EINVAL;
+	}
+
+	/* Decode channel */
+	hash   = readl(imc->window + CHANNEL_HASH_OFFSET);
+	s_size = imc->ch_s_size;
+	l_map  = imc->ch_l_map;
+	decode_addr(addr, hash, s_size, l_map, &idx, &sub_addr);
+	res->channel_idx  = idx;
+	res->channel_addr = sub_addr;
+
+	/* Decode sub-channel/DIMM */
+	hash   = readl(imc->window + CHANNEL_EHASH_OFFSET);
+	s_size = imc->dimm_s_size[idx];
+	l_map  = imc->dimm_l_map[idx];
+	decode_addr(res->channel_addr, hash, s_size, l_map, &idx, &sub_addr);
+	res->sub_channel_idx  = idx;
+	res->sub_channel_addr = sub_addr;
+
+	return 0;
+}
+
+static void igen6_output_error(struct decoded_addr *res,
+			       struct mem_ctl_info *mci, u64 ecclog)
+{
+	enum hw_event_mc_err_type type = ecclog & ECC_ERROR_LOG_UE ?
+					 HW_EVENT_ERR_UNCORRECTED :
+					 HW_EVENT_ERR_CORRECTED;
+
+	edac_mc_handle_error(type, mci, 1,
+			     res->sys_addr >> PAGE_SHIFT,
+			     res->sys_addr & ~PAGE_MASK,
+			     ECC_ERROR_LOG_SYND(ecclog),
+			     res->channel_idx, res->sub_channel_idx,
+			     -1, "", "");
+}
+
+static struct gen_pool *ecclog_gen_pool_create(void)
+{
+	struct gen_pool *pool;
+
+	pool = gen_pool_create(ilog2(sizeof(struct ecclog_node)), -1);
+	if (!pool)
+		return NULL;
+
+	if (gen_pool_add(pool, (unsigned long)ecclog_buf, ECCLOG_POOL_SIZE, -1)) {
+		gen_pool_destroy(pool);
+		return NULL;
+	}
+
+	return pool;
+}
+
+static int ecclog_gen_pool_add(int mc, u64 ecclog)
+{
+	struct ecclog_node *node;
+
+	node = (void *)gen_pool_alloc(ecclog_pool, sizeof(*node));
+	if (!node)
+		return -ENOMEM;
+
+	node->mc = mc;
+	node->ecclog = ecclog;
+	llist_add(&node->llnode, &ecclog_llist);
+
+	return 0;
+}
+
+/*
+ * Either the memory-mapped I/O status register ECC_ERROR_LOG or the PCI
+ * configuration space status register ERRSTS can indicate whether a
+ * correctable error or an uncorrectable error occurred. We only use the
+ * ECC_ERROR_LOG register to check error type, but need to clear both
+ * registers to enable future error events.
+ */
+static u64 ecclog_read_and_clear(struct igen6_imc *imc)
+{
+	u64 ecclog = readq(imc->window + ECC_ERROR_LOG_OFFSET);
+
+	if (ecclog & (ECC_ERROR_LOG_CE | ECC_ERROR_LOG_UE)) {
+		/* Clear CE/UE bits by writing 1s */
+		writeq(ecclog, imc->window + ECC_ERROR_LOG_OFFSET);
+		return ecclog;
+	}
+
+	return 0;
+}
+
+static void errsts_clear(struct igen6_imc *imc)
+{
+	u16 errsts;
+
+	if (pci_read_config_word(imc->pdev, ERRSTS_OFFSET, &errsts)) {
+		igen6_printk(KERN_ERR, "Failed to read ERRSTS\n");
+		return;
+	}
+
+	/* Clear CE/UE bits by writing 1s */
+	if (errsts & (ERRSTS_CE | ERRSTS_UE))
+		pci_write_config_word(imc->pdev, ERRSTS_OFFSET, errsts);
+}
+
+static int errcmd_enable_error_reporting(bool enable)
+{
+	struct igen6_imc *imc = &igen6_pvt->imc[0];
+	u16 errcmd;
+	int rc;
+
+	rc = pci_read_config_word(imc->pdev, ERRCMD_OFFSET, &errcmd);
+	if (rc)
+		return rc;
+
+	if (enable)
+		errcmd |= ERRCMD_CE | ERRSTS_UE;
+	else
+		errcmd &= ~(ERRCMD_CE | ERRSTS_UE);
+
+	rc = pci_write_config_word(imc->pdev, ERRCMD_OFFSET, errcmd);
+	if (rc)
+		return rc;
+
+	return 0;
+}
+
+static int ecclog_handler(void)
+{
+	struct igen6_imc *imc;
+	int i, n = 0;
+	u64 ecclog;
+
+	for (i = 0; i < res_cfg->num_imc; i++) {
+		imc = &igen6_pvt->imc[i];
+
+		/* errsts_clear() isn't NMI-safe. Delay it in the IRQ context */
+
+		ecclog = ecclog_read_and_clear(imc);
+		if (!ecclog)
+			continue;
+
+		if (!ecclog_gen_pool_add(i, ecclog))
+			irq_work_queue(&ecclog_irq_work);
+
+		n++;
+	}
+
+	return n;
+}
+
+static void ecclog_work_cb(struct work_struct *work)
+{
+	struct ecclog_node *node, *tmp;
+	struct mem_ctl_info *mci;
+	struct llist_node *head;
+	struct decoded_addr res;
+	u64 eaddr;
+
+	head = llist_del_all(&ecclog_llist);
+	if (!head)
+		return;
+
+	llist_for_each_entry_safe(node, tmp, head, llnode) {
+		memset(&res, 0, sizeof(res));
+		eaddr = ECC_ERROR_LOG_ADDR(node->ecclog) <<
+			ECC_ERROR_LOG_ADDR_SHIFT;
+		res.mc	     = node->mc;
+		res.sys_addr = res_cfg->err_addr_to_sys_addr(eaddr);
+		res.imc_addr = res_cfg->err_addr_to_imc_addr(eaddr);
+
+		mci = igen6_pvt->imc[res.mc].mci;
+
+		edac_dbg(2, "MC %d, ecclog = 0x%llx\n", node->mc, node->ecclog);
+		igen6_mc_printk(mci, KERN_DEBUG, "HANDLING IBECC MEMORY ERROR\n");
+		igen6_mc_printk(mci, KERN_DEBUG, "ADDR 0x%llx ", res.sys_addr);
+
+		if (!igen6_decode(&res))
+			igen6_output_error(&res, mci, node->ecclog);
+
+		gen_pool_free(ecclog_pool, (unsigned long)node, sizeof(*node));
+	}
+}
+
+static void ecclog_irq_work_cb(struct irq_work *irq_work)
+{
+	int i;
+
+	for (i = 0; i < res_cfg->num_imc; i++)
+		errsts_clear(&igen6_pvt->imc[i]);
+
+	if (!llist_empty(&ecclog_llist))
+		schedule_work(&ecclog_work);
+}
+
+static int ecclog_nmi_handler(unsigned int cmd, struct pt_regs *regs)
+{
+	unsigned char reason;
+
+	if (!ecclog_handler())
+		return NMI_DONE;
+
+	/*
+	 * Both In-Band ECC correctable error and uncorrectable error are
+	 * reported by SERR# NMI. The NMI generic code (see pci_serr_error())
+	 * doesn't clear the bit NMI_REASON_CLEAR_SERR (in port 0x61) to
+	 * re-enable the SERR# NMI after NMI handling. So clear this bit here
+	 * to re-enable SERR# NMI for receiving future In-Band ECC errors.
+	 */
+	reason  = x86_platform.get_nmi_reason() & NMI_REASON_CLEAR_MASK;
+	reason |= NMI_REASON_CLEAR_SERR;
+	outb(reason, NMI_REASON_PORT);
+	reason &= ~NMI_REASON_CLEAR_SERR;
+	outb(reason, NMI_REASON_PORT);
+
+	return NMI_HANDLED;
+}
+
+static bool igen6_check_ecc(struct igen6_imc *imc)
+{
+	u32 activate = readl(imc->window + IBECC_ACTIVATE_OFFSET);
+
+	return !!(activate & IBECC_ACTIVATE_EN);
+}
+
+static int igen6_get_dimm_config(struct mem_ctl_info *mci)
+{
+	struct igen6_imc *imc = mci->pvt_info;
+	u32 mad_inter, mad_intra, mad_dimm;
+	int i, j, ndimms, mc = imc->mc;
+	struct dimm_info *dimm;
+	enum mem_type mtype;
+	enum dev_type dtype;
+	u64 dsize;
+	bool ecc;
+
+	edac_dbg(2, "\n");
+
+	mad_inter = readl(imc->window + MAD_INTER_CHANNEL_OFFSET);
+	mtype = get_memory_type(mad_inter);
+	ecc = igen6_check_ecc(imc);
+	imc->ch_s_size = MAD_INTER_CHANNEL_CH_S_SIZE(mad_inter);
+	imc->ch_l_map  = MAD_INTER_CHANNEL_CH_L_MAP(mad_inter);
+
+	for (i = 0; i < NUM_CHANNELS; i++) {
+		mad_intra = readl(imc->window + MAD_INTRA_CH0_OFFSET + i * 4);
+		mad_dimm  = readl(imc->window + MAD_DIMM_CH0_OFFSET + i * 4);
+
+		imc->dimm_l_size[i] = MAD_DIMM_CH_DIMM_L_SIZE(mad_dimm);
+		imc->dimm_s_size[i] = MAD_DIMM_CH_DIMM_S_SIZE(mad_dimm);
+		imc->dimm_l_map[i]  = MAD_INTRA_CH_DIMM_L_MAP(mad_intra);
+		ndimms = 0;
+
+		for (j = 0; j < NUM_DIMMS; j++) {
+			dimm = edac_get_dimm(mci, i, j, 0);
+
+			if (j ^ imc->dimm_l_map[i]) {
+				dtype = get_width(0, mad_dimm);
+				dsize = imc->dimm_s_size[i];
+			} else {
+				dtype = get_width(1, mad_dimm);
+				dsize = imc->dimm_l_size[i];
+			}
+
+			if (!dsize)
+				continue;
+
+			dimm->grain = 64;
+			dimm->mtype = mtype;
+			dimm->dtype = dtype;
+			dimm->nr_pages  = MiB_TO_PAGES(dsize >> 20);
+			dimm->edac_mode = EDAC_SECDED;
+			snprintf(dimm->label, sizeof(dimm->label),
+				 "MC#%d_Chan#%d_DIMM#%d", mc, i, j);
+			edac_dbg(0, "MC %d, Channel %d, DIMM %d, Size %llu MiB (%u pages)\n",
+				 mc, i, j, dsize >> 20, dimm->nr_pages);
+
+			ndimms++;
+		}
+
+		if (ndimms && !ecc) {
+			igen6_printk(KERN_ERR, "MC%d In-Band ECC is disabled\n", mc);
+			return -ENODEV;
+		}
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_EDAC_DEBUG
+static void igen6_reg_dump(struct igen6_imc *imc)
+{
+	int i;
+
+	edac_dbg(2, "CHANNEL_HASH     : 0x%x\n",
+		 readl(imc->window + CHANNEL_HASH_OFFSET));
+	edac_dbg(2, "CHANNEL_EHASH    : 0x%x\n",
+		 readl(imc->window + CHANNEL_EHASH_OFFSET));
+	edac_dbg(2, "MAD_INTER_CHANNEL: 0x%x\n",
+		 readl(imc->window + MAD_INTER_CHANNEL_OFFSET));
+	edac_dbg(2, "ECC_ERROR_LOG    : 0x%llx\n",
+		 readq(imc->window + ECC_ERROR_LOG_OFFSET));
+
+	for (i = 0; i < NUM_CHANNELS; i++) {
+		edac_dbg(2, "MAD_INTRA_CH%d    : 0x%x\n", i,
+			 readl(imc->window + MAD_INTRA_CH0_OFFSET + i * 4));
+		edac_dbg(2, "MAD_DIMM_CH%d     : 0x%x\n", i,
+			 readl(imc->window + MAD_DIMM_CH0_OFFSET + i * 4));
+	}
+	edac_dbg(2, "TOLUD            : 0x%x", igen6_tolud);
+	edac_dbg(2, "TOM              : 0x%llx", igen6_tom);
+}
+#else
+static void igen6_reg_dump(struct igen6_imc *imc) {}
+#endif
+
+static int igen6_pci_setup(struct pci_dev *pdev, u64 *mchbar)
+{
+	union  {
+		u64 v;
+		struct {
+			u32 v_lo;
+			u32 v_hi;
+		};
+	} u;
+
+	edac_dbg(2, "\n");
+
+	if (!res_cfg->ibecc_available(pdev)) {
+		edac_dbg(2, "No In-Band ECC IP\n");
+		goto fail;
+	}
+
+	if (pci_read_config_dword(pdev, TOLUD_OFFSET, &igen6_tolud)) {
+		igen6_printk(KERN_ERR, "Failed to read TOLUD\n");
+		goto fail;
+	}
+
+	igen6_tolud &= GENMASK(31, 20);
+
+	if (pci_read_config_dword(pdev, TOM_OFFSET, &u.v_lo)) {
+		igen6_printk(KERN_ERR, "Failed to read lower TOM\n");
+		goto fail;
+	}
+
+	if (pci_read_config_dword(pdev, TOM_OFFSET + 4, &u.v_hi)) {
+		igen6_printk(KERN_ERR, "Failed to read upper TOM\n");
+		goto fail;
+	}
+
+	igen6_tom = u.v & GENMASK_ULL(38, 20);
+
+	if (pci_read_config_dword(pdev, MCHBAR_OFFSET, &u.v_lo)) {
+		igen6_printk(KERN_ERR, "Failed to read lower MCHBAR\n");
+		goto fail;
+	}
+
+	if (pci_read_config_dword(pdev, MCHBAR_OFFSET + 4, &u.v_hi)) {
+		igen6_printk(KERN_ERR, "Failed to read upper MCHBAR\n");
+		goto fail;
+	}
+
+	if (!(u.v & MCHBAR_EN)) {
+		igen6_printk(KERN_ERR, "MCHBAR is disabled\n");
+		goto fail;
+	}
+
+	*mchbar = MCHBAR_BASE(u.v);
+
+	return 0;
+fail:
+	return -ENODEV;
+}
+
+static int igen6_register_mci(int mc, u64 mchbar, struct pci_dev *pdev)
+{
+	struct edac_mc_layer layers[2];
+	struct mem_ctl_info *mci;
+	struct igen6_imc *imc;
+	void __iomem *window;
+	int rc;
+
+	edac_dbg(2, "\n");
+
+	mchbar += mc * MCHBAR_SIZE;
+	window = ioremap(mchbar, MCHBAR_SIZE);
+	if (!window) {
+		igen6_printk(KERN_ERR, "Failed to ioremap 0x%llx\n", mchbar);
+		return -ENODEV;
+	}
+
+	layers[0].type = EDAC_MC_LAYER_CHANNEL;
+	layers[0].size = NUM_CHANNELS;
+	layers[0].is_virt_csrow = false;
+	layers[1].type = EDAC_MC_LAYER_SLOT;
+	layers[1].size = NUM_DIMMS;
+	layers[1].is_virt_csrow = true;
+
+	mci = edac_mc_alloc(mc, ARRAY_SIZE(layers), layers, 0);
+	if (!mci) {
+		rc = -ENOMEM;
+		goto fail;
+	}
+
+	mci->ctl_name = kasprintf(GFP_KERNEL, "Intel_client_SoC MC#%d", mc);
+	if (!mci->ctl_name) {
+		rc = -ENOMEM;
+		goto fail2;
+	}
+
+	mci->mtype_cap = MEM_FLAG_LPDDR4 | MEM_FLAG_DDR4;
+	mci->edac_ctl_cap = EDAC_FLAG_SECDED;
+	mci->edac_cap = EDAC_FLAG_SECDED;
+	mci->mod_name = EDAC_MOD_STR;
+	mci->dev_name = pci_name(pdev);
+	mci->pvt_info = &igen6_pvt->imc[mc];
+
+	imc = mci->pvt_info;
+	device_initialize(&imc->dev);
+	/*
+	 * EDAC core uses mci->pdev(pointer of structure device) as
+	 * memory controller ID. The client SoCs attach one or more
+	 * memory controllers to single pci_dev (single pci_dev->dev
+	 * can be for multiple memory controllers).
+	 *
+	 * To make mci->pdev unique, assign pci_dev->dev to mci->pdev
+	 * for the first memory controller and assign a unique imc->dev
+	 * to mci->pdev for each non-first memory controller.
+	 */
+	mci->pdev = mc ? &imc->dev : &pdev->dev;
+	imc->mc	= mc;
+	imc->pdev = pdev;
+	imc->window = window;
+
+	igen6_reg_dump(imc);
+
+	rc = igen6_get_dimm_config(mci);
+	if (rc)
+		goto fail3;
+
+	rc = edac_mc_add_mc(mci);
+	if (rc) {
+		igen6_printk(KERN_ERR, "Failed to register mci#%d\n", mc);
+		goto fail3;
+	}
+
+	imc->mci = mci;
+	return 0;
+fail3:
+	kfree(mci->ctl_name);
+fail2:
+	edac_mc_free(mci);
+fail:
+	iounmap(window);
+	return rc;
+}
+
+static void igen6_unregister_mcis(void)
+{
+	struct mem_ctl_info *mci;
+	struct igen6_imc *imc;
+	int i;
+
+	edac_dbg(2, "\n");
+
+	for (i = 0; i < res_cfg->num_imc; i++) {
+		imc = &igen6_pvt->imc[i];
+		mci = imc->mci;
+		if (!mci)
+			continue;
+
+		edac_mc_del_mc(mci->pdev);
+		kfree(mci->ctl_name);
+		edac_mc_free(mci);
+		iounmap(imc->window);
+	}
+}
+
+static int igen6_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
+{
+	u64 mchbar;
+	int i, rc;
+
+	edac_dbg(2, "\n");
+
+	igen6_pvt = kzalloc(sizeof(*igen6_pvt), GFP_KERNEL);
+	if (!igen6_pvt)
+		return -ENOMEM;
+
+	res_cfg = (struct res_config *)ent->driver_data;
+
+	rc = igen6_pci_setup(pdev, &mchbar);
+	if (rc)
+		goto fail;
+
+	for (i = 0; i < res_cfg->num_imc; i++) {
+		rc = igen6_register_mci(i, mchbar, pdev);
+		if (rc)
+			goto fail2;
+	}
+
+	ecclog_pool = ecclog_gen_pool_create();
+	if (!ecclog_pool) {
+		rc = -ENOMEM;
+		goto fail2;
+	}
+
+	INIT_WORK(&ecclog_work, ecclog_work_cb);
+	init_irq_work(&ecclog_irq_work, ecclog_irq_work_cb);
+
+	/* Check if any pending errors before registering the NMI handler */
+	ecclog_handler();
+
+	rc = register_nmi_handler(NMI_SERR, ecclog_nmi_handler,
+				  0, IGEN6_NMI_NAME);
+	if (rc) {
+		igen6_printk(KERN_ERR, "Failed to register NMI handler\n");
+		goto fail3;
+	}
+
+	/* Enable error reporting */
+	rc = errcmd_enable_error_reporting(true);
+	if (rc) {
+		igen6_printk(KERN_ERR, "Failed to enable error reporting\n");
+		goto fail4;
+	}
+
+	return 0;
+fail4:
+	unregister_nmi_handler(NMI_SERR, IGEN6_NMI_NAME);
+fail3:
+	gen_pool_destroy(ecclog_pool);
+fail2:
+	igen6_unregister_mcis();
+fail:
+	kfree(igen6_pvt);
+	return rc;
+}
+
+static void igen6_remove(struct pci_dev *pdev)
+{
+	edac_dbg(2, "\n");
+
+	errcmd_enable_error_reporting(false);
+	unregister_nmi_handler(NMI_SERR, IGEN6_NMI_NAME);
+	irq_work_sync(&ecclog_irq_work);
+	flush_work(&ecclog_work);
+	gen_pool_destroy(ecclog_pool);
+	igen6_unregister_mcis();
+	kfree(igen6_pvt);
+}
+
+static struct pci_driver igen6_driver = {
+	.name     = EDAC_MOD_STR,
+	.probe    = igen6_probe,
+	.remove   = igen6_remove,
+	.id_table = igen6_pci_tbl,
+};
+
+static int __init igen6_init(void)
+{
+	const char *owner;
+	int rc;
+
+	edac_dbg(2, "\n");
+
+	owner = edac_get_owner();
+	if (owner && strncmp(owner, EDAC_MOD_STR, sizeof(EDAC_MOD_STR)))
+		return -ENODEV;
+
+	edac_op_state = EDAC_OPSTATE_NMI;
+
+	rc = pci_register_driver(&igen6_driver);
+	if (rc)
+		return rc;
+
+	igen6_printk(KERN_INFO, "%s\n", IGEN6_REVISION);
+
+	return 0;
+}
+
+static void __exit igen6_exit(void)
+{
+	edac_dbg(2, "\n");
+
+	pci_unregister_driver(&igen6_driver);
+}
+
+module_init(igen6_init);
+module_exit(igen6_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Qiuxu Zhuo");
+MODULE_DESCRIPTION("MC Driver for Intel client SoC using In-Band ECC");